Klarinet Archive - Posting 000512.txt from 1997/09

From: Daniel.Meirsman@-----.com
Subj: RE: Clarinet material
Date: Wed, 10 Sep 1997 11:52:25 -0400

--Boundary@-----.0_=0016800004397865

I suggest you guys all read the somewhat technical but otherwise excellent book
on acoustics of musical instruments by Bonade (available with Dover books).
Sometime ago another excellent book on the acoustics of wind instruments was
written Cornelius Nederveen. Unfortunately that one is out of print (it is
written in Dutch!).

========================================================
Daniel Meirsman
Belgium
e-mail: Daniel.Meirsman@-----.com
voice: +32 16 390 733
fax: +32 16 390 600
========================================================

-----Original Message-----
From: majordom@-----.us
Subject: Re: Clarinet material

I suggest that Jonathan contact the makers of Bach and Yamaha and tell
them that the thickness of the wall has nothing to do with the air
column vibrations which are caused by the lips vibrating. Their
research shows that the materials have everything to do with it.
Professional brass players remove laquer from their horns all the
time....that is considered a material. The concept that the material
has nothing to do with the way vibrations occur is absurd! Beyond that,
if you want to get technical, if the wall itself is not vibrating, the
material still contributes to the way the air column is excited. This is
precisely why Bach and Yamaha manufacture horn with varying thicknesses
of bell and leadpipe....note..I did not say bore size, I refer to
thickness of the material itself.

Roger Garrett

> NOT TRUE. Wall vibrations do not contribute audibly to the sound of a
brass > instrument. The air column vibrations create the sound in a
brass > instrument. This is TOTALLY different than the sound mechanism
on a > violin, which works as follows: > > * bow pulls across string
causing string to vibrate > * string vibrations are transmitted through
bridge to the top plate > of the violin > * top plate vibrations are
transmitted to the back plate by the > sound post > * back plate
vibrates moving a large mass of air and creating most > of the sound > >
On a brass instrument, the libs vibrate and excite the air column to >
vibrate. That's why these are also called "lip-reed" instruments. > > >
><< > >Perhaps it's not the tone (darkness...sorry Dan) that the > >
material affects but the projection of sound. Can softer materials
absorb > > sound more than harder materials? > >>> > >Yessiree. If the
material is really soft it will affect the sound. > > Certainly, if the
material is too soft, you won't even be able to make an > instrument out
of it. But any reasonably hard material such as wood, metal > or
plastic will work. FYI, the difference in thermal absorption between >
copper, brass, silver and wood is very small. Between the metals there
is > only a difference of at most .06 percent. Between the metals and
wood > there is a difference of just over 2 percent. > > Note that wood
absorbs 2 percent less thermal energy than metal does. > However,
because of losses due to porosity the combined losses of >
thermal/porosity effects is slightly greater in wood than in metal. For
a > highly polished, smooth dense wood, the difference from metal is in
the 2 > percent range, putting it just on the edge of detectability by
the player > (not by the listener). > > There are also viscous losses
due the flow of the air through the tube. > Even if the surfaces are
perfectly smooth, there will still be viscous > losses due, in essence
to the air rubbing against itself and the smooth > walls. > > Bottom
line, once again, the material doesn make any difference in real life. >
> > > ><< > >I always thought this was so. Part of > > "setting up" a
clarinet is polishing the bore; does this affect the > > sound/timbre of
the instrument? Again, I thought this was so. Please > > explain. > > >> >
>Can't explain... Don't know enough! But I do know that some say the
clarinet > >to buy is the one with a porous looking interior (see paper
by Hite I believe > >at his web site on barrels). > > > >I do think that
the level of polish on all commercially made professional > >instruments
is sufficiently high enough to produce the same effect though. If >
>there is such an effect, I would guess it would be affecting the way in
which > >standing waves are reflected inside the bore. Much in the same
way as frased > >holes affect the timbre of an instrument. > > > > As
I've mentioned in previous posts, having smooth surfaces and rounded >
corners (which you refer to as fraised holes) is VERY important and has
a > MAJOR effect on the playing character of a wind instrument. This is
due to > turbulence caused by rough or jagged surfaces. But again, this
is > independent of material. > > > > > -------------------------- >
Jonathan Cohler > cohler@-----.net > > >